Activities

Subshop A is parent of subshops A1 and A2.
Subshop A1 inherit price and inherit stock from it's parent.
Subshop A2 inherit price but it does not inherit stock from it's parent.
Subshop B does not inherit anything from other subshops.
Subshop C inherits everything from all other subshops.

Current situation:
Varnish caches objects with several parameters like domain and URL.
Shop form request to flush objects by meaningful URL and all matching wildcard (.*) for domain.
This means that if product X price changes Varnish will flush all objects having X as part of URL independently from domain. For example: http://.*/product_x